Battery and Electrical System Management

OBJECTIVE: The rescue team shall develop a set of standardized procedures for safe and effective shutdown of a fire or crash-damaged vehicles' electrical system based upon vehicle condition, position and situation so that the vehicle is safe and electrical hazards secured.

TASK: Given an acquired vehicle for training purposes, the rescuer team shall practice the various procedural steps listed in a new or revised electrical system shutdown protocol developed from this University of Extrication column.

The theme of vehicle batteries has appeared multiple times before in this University of Extrication series. We have addressed the challenge of trying to find a battery on a late-model vehicle, the fact that a vehicle can have multiple batteries, and we even looked at the concept of "power backfeeding"— a situation where an electronic device such as a computer or DVD player can feed it's electrical power back through critical components of the vehicle's electrical system even with the battery completely shut down.

This column is designed to give responding agencies the opportunity to develop a standard guideline or procedure for dealing with the electrical system on a crash-damaged (or fire-damaged) vehicle.

At a crash scene, there are various conditions that can be encountered. We know that not all vehicles involved in a crash are damaged the same way. A minor collision that you get called out to may have resulted in only minor vehicle damage and no injuries. That vehicle can be moved off the traveled roadway quickly to clear the highway and reduce exposure risk to personnel operating in or near moving traffic.

A major head-on collision may have people trapped when you pull up. You may arrive at a side-impact crash and find the car wrapped around a tree or bridge pillar. All these different conditions, positions and situations produce different resulting damage and affect procedures necessary to shut down the vehicle's electrical system. A policy describing the department's expectation for handling electrical systems can be based on this reality and written as a guideline that allows on-scene responders choices depending upon what they find when they arrive on the emergency scene.

Shutdown of a vehicle's electrical system used to be simple. Now, with today's complex vehicles and their engineered multiplex electrical systems, the process is a bit more involved if it is to be done correctly. Electrical system management involves a series of decisions, assessments and actions based on the conditions, positions and situation found on arrival. The three fundamental strategies include leaving all cables intact and doing nothing with the battery; disconnecting the battery cables in a non-destructive manner; or double-cutting all battery cables to completely take the battery out of the electrical circuit. Once it has been decided which action is appropriate, then the tactics can begin.

The following is an excerpt from a model standard operating procedure (SOP) written by this author for electrical system management at vehicle rescue incidents:

"Engine company crew is responsible for initial control of all existing or potential fire and safety hazards present at the emergency scene including control of moving traffic around the crash scene work area.

It shall be a standard practice of the engine company crew to deploy one portable dry chemical fire extinguisher. A minimum of one 1¾-inch fire safety handline with a minimum flow capability of 100 gpm shall be deployed at the discretion of the officer in charge, when a fuel leak/spill is present, or when extrication tasks are conducted.

Engine company personnel are responsible for initial stabilization of the damaged vehicles, electrical system management of all damaged vehicles and controlling any other hazards that are present now or may be present throughout the duration of the incident.

Engine company personnel assigned to electrical system shutdown also assume responsibility for unplugging any and all electrical accessory devices or appliances from the cigarette lighter and all accessory power ports inside the vehicle."

Vehicle Electrical Shutdown Tactical Procedures

When the decision has been made to disconnect or "double cut" the battery cables, the following training outline can help make sure that the process is efficient and that the desired outcome is achieved.

I. Inside Rescuer/EMS Responder

Once access is gained to passenger compartment, determine need for operation of any electrically powered features of the vehicle and activate features as deemed safe and appropriate:

Communicate with inside medical personnel to coordinate timing of electrical system shutdown. Advise that you have located the battery and intend to shut down electrical power. Request if they have operated interior electrical features or if they desire to operate electric door locks, power windows, trunk latch, etc, if safe and appropriate.

If tactic is to "double cut" cables, using a cutting tool, cut each ground (-) cable (typically black color) first using care not to touch any metal part of the chassis with the cable or your cutting tool, thus minimizing risk of creating a spark, then...

Cut each negative battery cable a second time to remove an approximately two inch-long section from each cable, preventing any unwanted electrical contact after task is completed...

Cut positive (+) battery cable(s), also cutting each "hot" cable a second time to remove a minimum two-inch section, completely taking the battery out of the electrical system, then...

Recheck that all cables or wires on all sides of the battery have been cut away from the battery, then…

Assess if there is any evidence that power from the battery is still running any part of the electrical system of the vehicle.

• Note that dome light should now be off, no interior door panel lights on an opened door are illuminated, horn and car radio are silent, headlights and parking lights are off, etc.

If electrical system remains energized after shutting down the obvious battery located under the hood, determine location of additional battery and repeat shutdown tactics for second battery, then...

Check the vehicle again to make sure it is not receiving electrical power, then...

VI. Report Power Shutdown Assignment Complete to Command

A standard benchmark for documentation of vehicle rescue activities should consist of a radio transmission to the communications center documenting vehicle power shutdown.

Totally shutting down a vehicle's electrical system does not ensure that loaded airbags inside the damaged vehicle will not accidentally deploy. Disconnecting the battery early in our rescue activities is, however, the most effective means of minimizing the potential for loaded airbag deployment, inadvertent electrical short circuits, or other unwanted events. Vehicle rescue is still a gamble against time for both the patient and the rescuer. By managing a vehicle's electrical system, as professionals, we are simply minimizing our risks.

TASK: Given an acquired vehicle for training purposes, the rescuer team shall practice the various procedural steps listed in a new or revised electrical system shutdown protocol developed from this University of Extrication column.

RON MOORE, a Firehouse® contributing editor, is a battalion chief and the training officer for the McKinney, TX, Fire Department. He also authors a monthly online article in the Firehouse.com "MembersZone" and serves as the Forum Moderator for the extrication section of the Firehouse.com website. Moore can be contacted directly at Rmoore@firehouse.com.

"Best practices" for battery management include three strategic options:

Leave the battery intact and all cables connected for situations such as:

Unoccupied, minor crash-damaged vehicle

Minor damage to vehicle, roadworthy condition, capable of being driven from scene

There is no unwritten rule out there that says that the fire department has to mess up the battery cables on every vehicle we encounter; get the big picture!

Disconnect cables in non-destructive manner for situations when:

Minor damage to vehicle with ambulatory patient seated inside vehicle; no entrapment or need for use of extrication tools or equipment

Access to battery and both terminal posts is good

Time to complete task is not a factor

Disconnecting at both battery terminal posts is possible rather than cutting cables

Common sense tells you that there is no realistic reason for you to cut cables other than you just like to and want to be destructive!

"Double cut" all battery cables for situations such as:

You encounter an occupied, crash-damaged vehicle with the EMS crew inside

There is a plan to commit power rescue tools to the damaged vehicle due to entrapment

Time is important and there is a true and realistic sense of urgency to take away electrical power

Access is limited to battery terminals or posts or some cables are obstructed

Under serious conditions such as listed here, "if in doubt, take it out"